A study of short-period variation in solar activity

作者：Chen Ji Long^*; Zhao Juan

来源：Research in Astronomy and Astrophysics, 2014, 14(8): 1011-1018.

DOI：10.1088/1674-4527/14/8/011

• Sun: activity
• Sun: sunspots
• methods: data analysis

We introduce two methods to detect short-period variation in solar activity. These are called amplitude of low frequency fluctuation (ALFF) and fractional amplitude of low frequency fluctuation (FALFF). We find a positive correlation between short-period variation and 11-year variation of solar activity using these two methods. Through ALFF, we find that solar activity over a short period becomes intensive when the 11-year solar activity is intensive. The ALFF value of the short period activity varies with the peak in sunspot number as a quadratic function. Through FALFF we find that the ratio of short-period spectral intensity to intensity over the whole period of solar activity will increase when the 11-year period of solar activity is intensive. The short-period FALFF value varies with the peak in sunspot number according to a cubic function. Using ALFF, we obtain a yearly series of solar activity that varies over a short period of 1-5 yr from 1860 to 2003, which shows an obvious periodicity of about 22 yr, 33 yr, 11 yr and a century. These short period variations show good correlations with long term variations in solar activity.

• 出版日期2014-8
• 单位北京师范大学